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Elec Fuel Pump flow ratings

Posted: Sun Aug 11, 2013 10:06 pm
by david martin
I've been reading about elec fuel pumps the last few nights and have a few questions. How are the pumps rated? I've come across terms like free flow rate, iph and Brake Specific Fuel Consumption but haven't found clear definitions.

I need to choose a pair of elec fuel pumps for my 1976 General boat with a mild 1967 Ford 289 and multiport injection. My fuel injectors flow 19 lb/hr.
I've read the best place for the pump is in the tank to aid in cooling and prevent a fire.

I would greatly appreciate any input pointing me in the right direction which pumps to consider. Reading resources or past experience would be great!

Thanks!

Re: Elec Fuel Pump flow ratings

Posted: Sat Oct 05, 2013 11:00 am
by Hey_Allen
By no means do I consider myself the authority, but here's what I understand on this.

Free flow rate on the pump is how many gallons per hour, or liters per hour the pump will move when unrestricted. For example, you could test this by pumping from one tank to another, or into a bucket. At peak pressure you will have a lower flow rate, but they are typically rated at a specific flow rate and pressure, as well as the free flow rate.

As to where to mount the pump and cooling of said pump, the fuel flowing through the pump is more efficient as a coolant than the fuel outside, but if your tank allows for it being inside already...
Many OEM's have done both ways. My Mercedes has an external pump, for whatever that's worth.
I've heard that part of the manufacturer's reasoning for going in tank was to knock down the audible whine of the pump in operation as much as anything else.